The Muses are the Greek goddesses who preside over the arts and sciences and inspire those who excel at these pursuits. Daughters of Zeus, king of the gods, and Mnemosyne ("memory"), they were born at Pieria at the foot of Mount Olympus. Their nurse, Eupheme, raised them along with her son, Crotus the hunter, who was transported into the sky as Sagittarius upon his death. Their name (akin to the Latin mens and English mind) denotes 'memory' or 'a reminder', since in the earlier times poets, having no books to read from, relied on their memories. The Romans identified the Muses with certain obscure Italian water-goddesses, the Camenae.

The original number of muses and their names varies in earlier times as their evolution blossomed in Greek mythology. At first, three muses were worshipped on Mount Helicon in Boeotia: Melete ("meditation"), Mneme ("memory"), and Aoede ("song"). Another three were worshipped at Delphi and their names represented the names of the strings of a lyre: Nete, Mese, and Hypate. Several other versions were worshipped until the Greeks finally established the nine muses in mythology as: Clio (History), Urania (Astronomy), Melpomene (Tragedy), Thalia (Comedy), Terpsichore (Dance), Calliope (Epic Poetry), Erato (Love Poetry), Polyhymnia (Songs to the Gods), Euterpe (Lyric Poetry).

Ephialtes and Otus, who also founded Ascra, were the first to sacrifice on Helicon to the Muses and to call the mountain sacred to the Muses. Sacrifices to the Muses consisted of libations of water, milk, or honey. Their companions are the Charities, the Horae, Eros, Dionysus, Apollo, Aphrodite, Harmonia, and Himerus (Desire). Apollo is the leader of the choir of the Muses and consequently he has the surname Musagetes.

Athena caught and tamed the winged horse Pegasus and gave him to the Muses. Some of their disciples included the Sphinx who learned her riddle from the Muses, Aristaeus, who learned the arts of healing and prophecy from them, and Echo, who was taught by them to play music.

In Plato's Phaedrus, Socrates says the locusts used to be men before the birth of the Muses. When song appeared when the Muses were born, some men were so overcome with delight that they sang constantly, forgetting to eat and drink until they eventually died. These dead men became locusts with a gift from the Muses allowing them to sing continuously from their birth until death without the need of sustenance. When they die, the locust go to the Muses and report which men on earth honors each, endearing a worshipper to the Muse he follows.

The Muses could be vindictive like in the story of the contest with Thamyris. Thamyris who excelled in minstrelsy challenged the Muses to a musical contest at Dorium in Messenia, the agreement being if he won he would take pleasure from all of them. The Muses won the contest, and bereft Thamyris of his eyes and minstrelsy.

In another story, the king of Emathia (Macedonia) and his wife Euippe had nine daughters and named them after the Muses. The daughters entered a contest with the Muses, were defeated and were metamorphosed by the Muses into birds called Colymbas, Iynx, Cenchris, Cissa, Chloris, Acalanthis, Nessa, Pipo, and Dracontis. These names were taken from actual names of birds such as the wryneck, hawk, jay, duck, goldfinch, and four others with no recognizable modern equivalents.

In yet another myth, it was said Hera, queen of the gods, persuaded the Sirens, who were described in early Greek mythology as having the bodies of birds and heads of beautiful women, to enter a singing contest with the Muses. The Muses won the competition and then plucked out all of the Sirens' feathers and made crowns out of them.

Many places were dedicated to the Muses such as the famous Valley of the Muses - Thespies on the eastern slopes of Mt. Helikon began it's "Mouseai" festivals in the 6th c. B.C. It was organized every 5 years by the Thespians. Poets and musicians from all over Greece also participated in various games (epic, poetry, rapsodia, kithara, aulos, satyric poetry, tragedy and comedy). It was common for ancient schools to have a shrine to the Muses called mouseion, the source of the modern word 'museum.' The famous Museum of Alexandria, founded by Ptolemy I, was a temple dedicated to the Muses. Before poets or storytellers recited their work, it was customary for them to invoke the inspiration and protection of the Muses.